What more can Israel do to limit civilian casualties? [Letter]

I notice that, in this most recent conflict between Israel and Hamas, there are widespread calls for Israel to "limit civilian casualties." President Barack Obama, U.N. Secretary General Ban Ki-Moon, and many other leaders of the free world repeat this over and over, without knowing exactly what they are asking for.

They call for limits on civilian casualties? Israel has done more than any other nation in the history of the world to do so. They fire warning shots, give citizens ample time to evacuate and call cell phones in advance! Look at it from the point of view of Israel: They are literally telling their enemies where they will strike hours before they do. What other country would give their opponents information like that in wartime? In the U.S., it's likely the entire Israeli military would be tried and convicted of espionage and aiding the enemy! All this in order to protect non-combatants. Limits on civilian casualties? If you ask me, "What can Israel do to further limit civilian casualties?" I will say the following: "What would you suggest?"